Heparin, whether normal (native, not fractionated) or partially degraded (fractionated), is an important anticoagulant. It is administered to persons with increased risk for blood clot formation, such as persons having undergone surgery or severe trauma or whose blood coagulation system is not well balanced, such in persons with risk for deep venous thrombosis. The drawback with this cheap and efficient drug is the requirement of administration by injection.